Crestview is the largest city in Okaloosa County, Florida, United States. The population was 27,134 at the 2020 census, up from 20,978 at the 2010 census. It is the county seat of Okaloosa County. With an elevation of 236 feet above sea level, it is one of the highest points in the state. Crestview is a principal city of the Crestview–Fort Walton Beach–Destin, Florida Metropolitan Statistical Area.